A Look at Two Studies Connecting Diabetes & Brain Function

By By Dr. Nadeau

Dr. Nadeau is an accomplished physician who brings extensive experience
to the Mary & Dick Allen Diabetes Center as Program Director, Dr.
Kris V. Iyer Endowed Chair in Diabetes Care and Endocrinologist at Hoag
Medical Group . While he has many areas of interest, the majority of his
recent work, research, and lectures focus on diabetes, obesity, and nutrition.

The importance of glucose control has been highlighted in two new studies
that look at diabetes and brain function:

Washington University, St. Louis has done studies recently on mice that
purposed the idea that "Diabetes may pose a risk for Alzheimer’s."
Researchers found that abnormal high levels of blood sugar correlates
to an increase in amyloid beta proteins in the brain, which is a risk
factor for Alzheimer’s disease. This is important because
Type 2 Diabetes
(T2D) affects about 29 million people in the U.S. and may lead to other
complications such as heart disease, blindness, and death. It is the most
common form of diabetes where the body becomes desensitized to insulin.
Type 1 Diabetes
(T1D) usually starts in childhood as the pancreas does not produce sufficient
amount of insulin, a naturally occurring hormone in the body. Both of
these types lead to poor sugar metabolism by the cells, which leads to
higher than normal blood sugar levels.

Based on a recent study at the University of Pittsburgh, it was found
that T1D patients had significantly more brain lesions and slower cognitive
function than people without diabetes. There were a total 180 people in
this study. One group was comprised of people with T1D with an average
age of 50 and another group was non- diabetic patients with an average
age of 45. They found that uncontrolled blood sugar has negative clinical
effects on the brain over the time, and in some cases even before symptoms
of dementia appear. It can affect the speed with which your brain works
and how quickly your brain passes information from one part to another
part. The lead researcher, Caterina Rosano was surprised because the study
participants were so young.

In the Washington University study, the mice’s brains were engineered
to resemble an Alzheimer’s patient. As a high dose of sugar was
given over a few hours, amyloid beta levels increased in brain cells.
However, this can only suggest a relationship between blood sugar levels
and amyloid production rather than the development of Alzheimer’s.
Similarly, Dr. Holtzman says "high blood sugar appears to affect
the way the brain functions." Does this mean insulin may improve
brain function such as memory? Dr. Craft’s research suggests improvement
in mild memory impairments has been noted with stimulation of insulin
production in early Alzheimer’s patient.

Future studies need to be done to conclude such a relationship between
diabetes as a risk factor for Alzheimer’s disease.

New technology such as glucose sensors and insulin pumps can dramatically
improve glucose in T1D and newer medications have helped revolutionize
care in T2D.